Stewed, is greasy (5)
I believe the answer is:
oiled
I believe this clue is a double definition.
'stewed' is the first definition.
(thesaurus)
'greasy' is the second definition.
(I've seen this before)
'is' is the link.
(Other definitions for oiled that I've seen before include "Anointed" , "Lubricated or drunk" , "Cut" , "Lubricated (with drink?)" , "get drunk" .)